This invention relates to tire inflation machines used in OEM production line operations, and more particularly to tire inflation machines designed to accommodate different tire sizes.
In modern automotive vehicle plants, automated equipment is used to assemble and inflate tires on wheels in preparation for mounting on a vehicle. Prior to inflation, the tire is mounted on the wheel, usually at a separate mounting station, and in some instances the tire is then angularly aligned relative to the wheel to minimize the overall runout of the tire/wheel assembly. See, for example, U.S. Pat. No. 5,826,319 to Colwell et al. At a typical tire inflation station, the uninflated wheel-mounted tire is conveyed onto a stationary tire platen beneath an overhead tire inflation bell. Centering arms then engage the tire and center it into alignment with the overhead inflation bell. The inflation bell is then moved downwardly into engagement with the wheel-mounted tire and inflation air is delivered into the interior of the tire around its inner peripheral bead. The head is then retracted allowing the bead of the tire to seat and seal against the outer peripheral rim of the wheel.
As described in U.S. Pat. No. 6,148,892, issued Nov. 21, 2000 to A. Koerner and hereby incorporated herein by reference, a conveyor belt delivers the wheel-mounted tire to the tire platen (bed) of the tire inflation station. To assist in the alignment of the tire relative to the vertical axis of the inflation bell, the bed may be floated on a cushion of air for near-frictionless centering of the tire.
Although the bed of the typical tire inflation station is capable of handling tires of varying outer diameters, the bell housing is typically limited to tires having a specific inner bead diameter, or rim diameter. In addition, a typical station may be capable of only inflating tires of a single width, with manual adjustment or tool changes being necessary when switching to tires of differing diameter or width. Some approaches for providing automated handling of different sized tires have been proposed. In U.S. Pat. No. 5,509,456 to Bonko et al., a segmented manifold is used to supply the inflation air. The manifold can be expanded radially to accommodate different sizes of tires. U.S. Pat. No. 5,072,765 discloses an auxiliary tire bead depressor for use with an inflation machine to permit a single inflation bell to be used in conjunction with different sized tires. The tire bead depressor comprises a shaft that depresses the tire sidewall at a location between the inflation bell""s outer seal ring and the wheel (rim) to prevent premature seating of the bead when the machine is used with a tire and wheel having a relatively small diameter when compared to that of the inflation bell""s outer seal ring.
In accordance with the invention there is provided a tire inflation apparatus for use in sequentially inflating a plurality of wheel-mounted tires that can have differing diameters and/or widths. The apparatus includes a base having a tire platen or other support surface upon which the tire being inflated is first loaded. A first bell housing is supported by the base for movement toward and away from the tire support surface, with the first bell housing moving along an axis between a retracted position and an extended position. A second bell housing is also supported by the base for movement along the axis toward and away from the tire support surface between retracted and extended positions. The first bell housing is used in conjunction with larger-sized wheel-mounted tires and the second bell housing is used with smaller-sized tires. The first bell housing is constructed such that, when in its extended position, it will mate with a larger-sized wheel-mounted tire to thereby define a first air chamber between the tire and first bell housing. The second bell housing is constructed such that, when in its extended position, it will mate with a smaller-sized wheel-mounted tire to thereby define a second air chamber between the tire and second bell housing. The second bell housing is located within the first air chamber when the second bell housing is in its retracted position and the first bell housing is in its extended position. This permits a single compressed air supply tap located within the second bell housing to be used for inflation of both the larger and smaller-sized tires.
Preferably, the first and second bell housings are nested and can extend telescopically, with the first bell housing comprising an outer bell housing the substantially encloses the second, inner bell housing. This can be accomplished using a bell assembly that includes the first and second bell housings along with one or more actuators for telescoping the inner bell housing in and out of the outer bell housing. The bell assembly is supported by the base and is movable as a unit using one or more bell housing actuators. By moving the entire bell assembly with the inner bell housing in its retracted position, the outer bell housing can be moved between from its retracted position into its extended position while the inner bell housing is maintained in its retracted position inside the outer bell housing, and this arrangement permits use of the outer bell housing for inflation of larger-sized tires. Then, for smaller-sized tires, the inner bell housing can be telescoped out of the outer bell housing.
Preferably, a programmable electrical controller controls actuation of the inner bell housing and bell assembly actuators which is dictated by the size or diameter of the tires. Also, the controller establishes the distance between the assembly""s extended and retracted positions by taking reference from an elongated linear measurement sensor engaged vertically to the bell assembly. The distance between assembly positions is dictated by the thickness of the tire, or distance between sidewalls. Control of the length of travel of the bell assembly can then be accomplished using one or more hydraulic stops.
An advantage of the present invention is the ability to inflate either a large or small wheel-mounted tire without requiring a manual hardware alteration of the tire inflation apparatus.